From df4462b43661d56cba2b1e0fa8a2408a7554b81c Mon Sep 17 00:00:00 2001
From: Jacob Signorovitch <jacob.signorovitch@gmail.com>
Date: Mon, 25 May 2026 13:18:48 -0400
Subject: [PATCH] Yes

---
 15-compilation-part-2/main.rkt | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/15-compilation-part-2/main.rkt b/15-compilation-part-2/main.rkt
index 2b74379..552d360 100644
--- a/15-compilation-part-2/main.rkt
+++ b/15-compilation-part-2/main.rkt
@@ -15,6 +15,8 @@
            | { <TOY> <TOY> ... }
 |#
 
+(define-type BINDINGS (Listof (Listof Symbol)))
+
 ;; A matching abstract syntax tree datatype:
 (define-type TOY
   [Num  Number]
@@ -185,23 +187,23 @@
 ;; a global flag that can disable the compiler
 (define compiler-enabled? (box #f))
 
-(: compile-body : (Listof TOY) -> (ENV -> VAL))
+(: compile-body : (Listof TOY) BINDINGS -> (ENV -> VAL))
 ;; compiles a list of expressions to a single Racket function.
-(define (compile-body exprs)
+(define (compile-body exprs bin)
   (unless (unbox compiler-enabled?)
     (error 'compile-body "compiler disabled"))
-  (let ([compiled-1st (compile (first exprs))]
+  (let ([compiled-1st (compile (first exprs) bin)]
         [rest         (rest exprs)])
     (if (null? rest)
       compiled-1st
-      (let ([compiled-rest (compile-body rest)])
+      (let ([compiled-rest (compile-body rest bin)])
         (lambda (env)
           (define ignored (compiled-1st env))
           (compiled-rest env))))))
 
-(: compile-get-boxes : (Listof TOY) -> (ENV -> (Listof (Boxof VAL))))
+(: compile-get-boxes : (Listof TOY) BINDINGS -> (ENV -> (Listof (Boxof VAL))))
 ;; utility for applying rfun
-(define (compile-get-boxes exprs)
+(define (compile-get-boxes exprs bin)
   (: compile-getter : TOY -> (ENV -> (Boxof VAL)))
   (define (compile-getter expr)
     (cases expr
@@ -218,9 +220,9 @@
       (map (lambda ([get-box : (ENV -> (Boxof VAL))]) (get-box env))
            getters))))
 
-(: compile : TOY -> (ENV -> VAL))
+(: compile : TOY BINDINGS -> (ENV -> VAL))
 ;; compiles TOY expressions to Racket functions.
-(define (compile expr)
+(define (compile expr bin)
   ;; convenient helper for running compiled code
   (: caller : ENV -> ((ENV -> VAL) -> VAL))
   (define (caller env)